diff options
Diffstat (limited to 'src/cryptography/hazmat/backends/openssl/x25519.py')
-rw-r--r-- | src/cryptography/hazmat/backends/openssl/x25519.py | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/src/cryptography/hazmat/backends/openssl/x25519.py b/src/cryptography/hazmat/backends/openssl/x25519.py new file mode 100644 index 00000000..f92b184b --- /dev/null +++ b/src/cryptography/hazmat/backends/openssl/x25519.py @@ -0,0 +1,71 @@ +# This file is dual licensed under the terms of the Apache License, Version +# 2.0, and the BSD License. See the LICENSE file in the root of this repository +# for complete details. + +from __future__ import absolute_import, division, print_function + +from cryptography import utils +from cryptography.hazmat.primitives.asymmetric.x25519 import ( + X25519PrivateKey, X25519PublicKey +) + + +@utils.register_interface(X25519PublicKey) +class _X25519PublicKey(object): + def __init__(self, backend, evp_pkey): + self._backend = backend + self._evp_pkey = evp_pkey + + def public_bytes(self): + ucharpp = self._backend._ffi.new("unsigned char **") + res = self._backend._lib.EVP_PKEY_get1_tls_encodedpoint( + self._evp_pkey, ucharpp + ) + self._backend.openssl_assert(res == 32) + self._backend.openssl_assert(ucharpp[0] != self._backend._ffi.NULL) + data = self._backend._ffi.gc( + ucharpp[0], self._backend._lib.OPENSSL_free + ) + return self._backend._ffi.buffer(data, res)[:] + + +@utils.register_interface(X25519PrivateKey) +class _X25519PrivateKey(object): + def __init__(self, backend, evp_pkey): + self._backend = backend + self._evp_pkey = evp_pkey + + def public_key(self): + bio = self._backend._create_mem_bio_gc() + res = self._backend._lib.i2d_PUBKEY_bio(bio, self._evp_pkey) + self._backend.openssl_assert(res == 1) + evp_pkey = self._backend._lib.d2i_PUBKEY_bio( + bio, self._backend._ffi.NULL + ) + return _X25519PublicKey(self._backend, evp_pkey) + + def exchange(self, peer_public_key): + if not isinstance(peer_public_key, X25519PublicKey): + raise TypeError("peer_public_key must be X25519PublicKey.") + + ctx = self._backend._lib.EVP_PKEY_CTX_new( + self._evp_pkey, self._backend._ffi.NULL + ) + self._backend.openssl_assert(ctx != self._backend._ffi.NULL) + ctx = self._backend._ffi.gc(ctx, self._backend._lib.EVP_PKEY_CTX_free) + res = self._backend._lib.EVP_PKEY_derive_init(ctx) + self._backend.openssl_assert(res == 1) + res = self._backend._lib.EVP_PKEY_derive_set_peer( + ctx, peer_public_key._evp_pkey + ) + self._backend.openssl_assert(res == 1) + keylen = self._backend._ffi.new("size_t *") + res = self._backend._lib.EVP_PKEY_derive( + ctx, self._backend._ffi.NULL, keylen + ) + self._backend.openssl_assert(res == 1) + self._backend.openssl_assert(keylen[0] > 0) + buf = self._backend._ffi.new("unsigned char[]", keylen[0]) + res = self._backend._lib.EVP_PKEY_derive(ctx, buf, keylen) + self._backend.openssl_assert(res == 1) + return self._backend._ffi.buffer(buf, keylen[0])[:] |